Having spent some time in Japan, I have learnt of the tradition of holding a Bōnenkai, literally a party to forget the year. Held either as a company end-of-year party, or by groups of friends, it’s a get-together in which people drink a lot and forget the bad things that happened to them during the year.
It occurred to me that this is the complement of Thanksgiving, in which you get together to remember the good things that happened during the year.
I don’t think there is anything else left to say about the difference between Japanese and American culture.
Interestingly, there are a couple more possibilities. One could remember the bad things that happened during the year, as in the airing of grievances during Festivus.
Finally, one could forget the good things, which is very much the Italian attitude.
Edited to add: I don’t know how I forgot (ah!) but there is a famous Neapolitan folk song that goes
Chi ha avuto, ha avuto, ha avuto
Chi ha dato, ha dato, ha dato,
Scurdammuce ‘o passato,
simm’e Napule, paisa’
which is roughly
Who has received, has received
Who has given, has given,
Let’s forget the past
We are [all] from Naples
in theory 
Obviously, the complement of Bōnenkai, as per your description, would be to remember one bad thing 🙂
At least one bad thing, if math-logical complement is meant.